Women’s stronger immune response to vaccinations diminishes with age: study
| Jul 17, 2019, 17:56 IST
According to a study from the researchers at the Johns Hopkins Bloomberg School of Public Health, women have a better immune response to a flu vaccination than men but this advantage is largely ineffective as they age as their estrogen levels decline.
The research team had evaluated responses to the flu vaccine in 50 adults between the age 18-45 years and 95 adults aged 65 and older. The results of the study said that the younger group had a stronger immune response when compared to older women and all men. Experiments on mice also yielded similar results and suggested that estrogen -- levels of which lessen with age in females -- boosts females' immune responses to flu vaccines, while testosterone lowers males' responses. The scientists expect that their results will be generalizable to other vaccines.
"We need to consider tailoring vaccine formulations and dosages based on the sex of the vaccine recipient as well as their age," says study senior author Sabra Klein, Ph.D., an associate professor in the Department of Molecular Microbiology and Immunology at the Bloomberg School.
The scientists first evaluated immune responses to the 2009 H1NI1 influenza vaccine in 145 human volunteers - one group age 18-45 years, the other 65 and older. They found that on average, women in the younger group had a stronger response compared to both the men and the older women. The younger women had, for example, a jump in their levels of the important immune protein IL-6 that was almost three times greater than that seen in the younger men, and almost double that seen in older women. Measures of the anti-flu antibody response also were higher for the younger women compared to the men and the older women, though the greatest differences were between the younger and older women.
"What we show here is that the decline in estrogen that occurs with menopause impacts women's immunity," Klein says. "Until now, this hasn't been considered in the context of a vaccine. These findings suggest that for vaccines, one size doesn't fit all -- perhaps men should get larger doses, for example."
She and her colleagues are now investigating the molecular mechanisms by which estradiol and other estrogens boost the antibody response to vaccines.
The research team had evaluated responses to the flu vaccine in 50 adults between the age 18-45 years and 95 adults aged 65 and older. The results of the study said that the younger group had a stronger immune response when compared to older women and all men. Experiments on mice also yielded similar results and suggested that estrogen -- levels of which lessen with age in females -- boosts females' immune responses to flu vaccines, while testosterone lowers males' responses. The scientists expect that their results will be generalizable to other vaccines.
"We need to consider tailoring vaccine formulations and dosages based on the sex of the vaccine recipient as well as their age," says study senior author Sabra Klein, Ph.D., an associate professor in the Department of Molecular Microbiology and Immunology at the Bloomberg School.
The scientists first evaluated immune responses to the 2009 H1NI1 influenza vaccine in 145 human volunteers - one group age 18-45 years, the other 65 and older. They found that on average, women in the younger group had a stronger response compared to both the men and the older women. The younger women had, for example, a jump in their levels of the important immune protein IL-6 that was almost three times greater than that seen in the younger men, and almost double that seen in older women. Measures of the anti-flu antibody response also were higher for the younger women compared to the men and the older women, though the greatest differences were between the younger and older women.
"What we show here is that the decline in estrogen that occurs with menopause impacts women's immunity," Klein says. "Until now, this hasn't been considered in the context of a vaccine. These findings suggest that for vaccines, one size doesn't fit all -- perhaps men should get larger doses, for example."
She and her colleagues are now investigating the molecular mechanisms by which estradiol and other estrogens boost the antibody response to vaccines.